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UNITED STATES PATENT OFFICE.

CHARLES D. ROGERS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE AMERICAN SCREW COMPANY, OF SAME PLACE.

SCREW-SWAGING MACHINE.

SPECIFICATION forming part of Letters Patent No. 393,484, dated November 27, 1888.

Application filed June 11, 1888. Serial No. 276,732. (No model.)

To all whom it may concern:

Be it known that 1, CHARLES D. ROGERS, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Blank-Supporting Devices for Screw-Threading Machines; and I do herebydeclarethe followingto beafull,clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

In the production of screws, but more es pecially in the manufacture of wood-screws in which the threads are impressed into the surface of the blank by means of the ribs of suitably mounted and operated dies, it is the practice, so far as I am aware, to support the blank during the rolling operation by means of a guide,upon which the head of the blank bears; or in some cases the point of the blank rests upon a plane surface. An objection to such former methods of supporting the blanks is that, owing to the lack of uniformity in the pointed portions of the blanks, they are improperly introduced to the threading-dies.

In the operation of pointing the blanks or reducing the end portion to a cone shape the metal is compressed somewhat by the action of the cutting-off and shaping dies, and as it is practicallyimpossible to accurately gage the amount of metal required to form the pointit follows that the points become more or less elongated. It is evident, now,that if the point of the blank rests upon a bottom support or table the base of the cone, which joins the cylindrical part of the blank,will not in all cases coincide with the angle formed in the working. face of the threading-dies. If the blank enters too high, the thread produced upon the point will be too thick and partially formed, and consequently imperfect. If it enters too low, there will be a surplus of metal, and, as there is no place for it to escape, the blank becomes clogged between the dies, thereby producing an immense strain upon and occasionally fracturing them, the blanks obviously being imperfect.

From the foregoing it is apparent that to produce screws having perfect threads upon the point portion it is essential that the base of the cone and the angle formed in the workingface of the dies must always coincide. In order to attain this result, I provide each threading-die at its front end with athin strip of metal having the adjacent upper edges beveled or otherwise adapted to receive the point of the blank between them, and also arranged to sustain the blank in position until the dies begin to act fairly upon it. By means of this arrangement the blank is supported near the base of the cone-shaped point, the size or diameter thereof at the point of contact being practically alike in all the blanks when made from the same size or gage of wire. It is evident, now, by holding the blank in position laterally that the supports will properly present the blanks to the dies.

In an application for United States Letters Patent,-filed by me May 18, 1888, Serial No. 274,275, I have shown, described, and claimed a machine for automatically screwthreading blanks by means of reciprocating threadingdies.

In the drawings annexed, Figure 1 represents a plan view of a screw-threading ma chine of the character indicated above, aportion of the feeding mechanism being removed and showing a blank supported in position preparatory to being acted upon by the threading-dies. Fig. 2 is an enlarged side view, in partial section, taken through the center of the machine, showing a portion of a feeding device having a blank therein supported by metallic strips, which engage the upper portion of the blanks point and corresponding to the position shown in Fig. 1. Fig. 3 is an on larged transverse sectional view taken through the line a: m of Fig. 1, showing the relation of the blank to the dies, supporting device, 850. Fig. 4 is a similar sectional view, still further enlarged, showing only the two supportingbars and the blank resting thereon, all the foregoing figures being referable to the position of the blank prior to its engagement with the threading-dies. Fig. 5 is a view of the lower portion of a wood-screw blank havinga normally proportioned cone shaped point; and Fig. 6 is a view of the end of a blank, showing the tendency of the point to elongate in case a slight excess of metal be presentduring the cutting-off and pointing operation.

A more detailed description of my present invention is as follows:

5, Referring to Fig. 1, in which is represented a machine for swaging or rolling screw-threads upon blanks, a (1. indicate two crossheads mounted in ways formed in the main frame 7). These cross-heads are oppositely arranged,

and are adapted to travel back and forth past each other by means of the gearing and con fneelions, as clearly shown. I make no claim herewith to this or any specific operating mechanism; neither do I claim herewith the 1 hopper c and feeding mechanism, which conducts the blanks m therefrom to the supporting device. To each cross-head is secured a threadingdie, d, the two dies coacting to roll a screw-thread upon and into the shank and point of the blank, as common. A die for this purpose is shown and claimed in United States Patent No. 370,354, granted to me September 20, 1887. To the forward end of each die, or to holders 0, in which the dies are mounted, is se- 2 5 cu red athin piece orbar of metal, 8, the same extending in front of and past each other when the dies are in the extreme position shown in Fig.

1, and preparatory to acting upon the blanks. These bars 8 are susceptible of vertical adjust- 0 ment by means of screws passing through the slotted openings 8. I prefer to bevel off -the upper inner edges of the bars, as indicated by u, to correspond somewhat with the angle of the blanks pointp. By means of this arrange- 5 ment the vertical distance from the upper edge of the bars to the base-line c of the point will always be the same for blanks of the same gage of wire. It is obvious, however, that this distance may be varied by a readjustment of the bars in a lateral direction, thereby affecting the width of the space 8 lying between them.

In Fig. 2 is shown a device for automatically conducting the blanks to the supporting-bars 5 s. This arrangement is described more at length in my pending application, before referred to. I would state, however, that ff indicate jaws, which are adapted to be inter mittingly opened and closed at the proper time by actuated cam-plates i 5. (Shown sectionally.) The lower portion, f, of the jaws is reduced in thickness and extends downwardly into the space formed by the separation of the dies (1!. The meeting faces of the 5 5 lower portion are slightly concave to receive and hold the blanks in position laterally. A

checking-plate, mounted in the upper part of the feeding device, is made to travel back and forth through the medium of a cam-plate,

6c *5, thereby uncovering the runway or track and permitting a blank to enter the feed-bo;\', after which the plate forces it therefrom into the enlarged space 75, from which it falls into the jaws f, and is arrested and supported by the bars 8.

From the foregoing it is evident that blanks having points 1) of unequal lengths, as shown in Figs. 5 and 6, will, when supported by the bars 8, be uniformly presented to the threading-dies, the diameters at the points z, indieating, say, the line of support, being the same. If, however, the blanks be supported at the lower ends, as upon a surface, w, Figs. 5 and 6, it is apparent that the blank shown in Fig. 6 would carry the point 0 far too high when presented to the dies (1, as compared with the pointed portion p. (Shown in Fig. 5.) In these cases the length of the blanks is supposed to be the same from the base a of the cone of the point to the head 71 By reason of my improved method of supporting blanks the tip or extreme end of the point is preserved, which otherwise becomes more or less blunted before the blank reaches the threading-dies.

It is obvious that the form and arrangement of the supporting-bars 8 may be changed or modified somewhat without departing from the spirit of the invention. I prefer to employ blanks at having. a cone-shaped .point. The heads may be slotted or not, as desired.

In the drawings I have represented both dies as 'traveling; but the blank-supporting device is equally operative and practical in a machine having one die stationary and the other driven, in which case a traveling carrier would be employed. A machine ofthis construction, without my present improvement, is shown in my United States Patent No. 370,353, of September, 20, 1887.

I claim as my invention 1. In ascrew-threading machine, the combination of holdingjaws for guiding the blanks laterally and presenting them to the threading mechanism, a series of thread-forming dies, and combined blank supporting and guiding plates mounted in advance of said dies, all arranged and operating substantially as herein before described.

2. In a scrcw-threadin g machine, the combinatiou,with' the threading-dies, of bars or ribs mounted in advance of the dies and traveling in unison therewith, said bars or ribs being separated and adapted to receive the point portion of the blanks, substantially as described, and for the purpose set forth.

3. In a screw-threading machine, the combination, with actuated blank holding jaws constructed to support the blank laterally, of oppositely mounted and actuated threading-dies and bars, as s, mounted in advance of and moving in unison with the dies, and having the upper edges of the bars separated and arranged to receive the sides of the point of the blank, so as to support the blank and properly introduce it to the dies, substantially as set forth.

L. In a scrcw-threadin g machine, the combination, with threading-dies and holding-jaws,

of two parallel adj ustably mounted and actuinto engagement with the thread-forming dies, the same consisting of supporting-bars mounted in advance of and arranged to travel in unison with the said thread-forming dies, the bars being separated to receive the points of the blanks, but not admitting the cylindrical portion of the blanks between them, substantially as described.

In testimony whereof I have affixed my signature in presence of two witnesses.

CHARLES D. ROGERS. Witnesses:

CHARLES HANNIGAN, GEO. H. REMINGTON. 

